PluginContext.constructors.Request(request, data) does not replicate headers

[scottinet]

When building a new Request object for plugins, using PluginContext.constructors.Request, we should copy almost all informations from the provided Request.

This is to help plugin developers, as it has been found confusing for them to understand why the new Request object is almost empty, since they provide the source request.

Additional information to replicate in the new request object:

• request.input.args: contains protocol headers, which should be replicated to the new request object. Same goes for request specific arguments, which will be overridded anyway by plugin developers if needed
• request.input.resource: plugin developer will always override these if needed, and it seems normal that the new request point to the same resources than the provided one